This invention relates to turn latch assemblies and, in particular, to turn latch assemblies that may be multiply configured by an operator to suit the requirements of a particular closure.
A typical latch involves two principal positions: a first position in which the latch is engaged with an external catch, wall, or other barrier; and a second position in which the latch is disengaged from the external catch. The typical latch is configured to operate between these two positions and may not easily be disassembled and reassembled to obtain a different pair of first and second positions. Thus, the typical latch dictates what the first and second positions are, and, consequently, is of use only in connection with those closure arrangements designed to require precisely those first and second positions. As a result, the typical latch is useful in only a single closure arrangement.
Some latches have addressed this limitation by being relatively easily disassembled and reassembled in a limited number of predetermined latch configurations. Accordingly, such a latch provides the operator with a limited number of options so that the latch may be used in more than one closure arrangement. Such a latch may be thereby conformed to the requirements of a limited number of tasks.
As an example of this, U.S. Pat, No. 5,509,703 discloses a quarter-turn latch that may be disassembled and reassembled by the operator in any one of four possible configurations such that the engagement arm of the latch can operate in any one of the four 90xc2x0 quadrants around a central axis of rotation. That is, the latch may be assembled to have one of four possible combinations of first and second positions. Thus, according to the disclosure, the engagement arm may operate in the range of either 0xc2x0 to 90xc2x0, 90xc2x0 to 180xc2x0, 180xc2x0 to 270xc2x0, or 270xc2x0 to 360xc2x0 (i.e., 0xc2x0).
One problem with the above-mentioned latch, however, is that while it appears to offer four options, the latter two options are redundant with the former two options. That is, the latter two options may be achieved simply by rotating the entire latch housing itself 180xc2x0. Thus, the configuration of the latch disclosed in that patent provides for the latter two options is unnecessary and redundant. Many rotatable latches that do not otherwise provide for alternative configurations have housings that may be mounted in either a first or a second orientation such that the second orientation is rotated 180xc2x0 from the first orientation.
Another problem with the above-mentioned latch and latches assemblies having such combination of mechanisms is that they provide configuration options for only clockwise operation. Yet another problem with the above-mentioned latch is that it is strictly a quarter-turn latch; it does not provide an option where it may be operated throughout a 180xc2x0 range (i.e., a half-turn latch option).
The present invention relates to a latch assembly, and in particular, a latch assembly that may be assembled in any one of a number of configurations such that the range of operation of the latch can be made to conform to the particular needs of many different closures. The preferred embodiment of the present invention relates in particular to a rotation latch assembly that may be assembled as either a quarter-turn latch or a half-turn latch, and as either a clockwise latch or a counter-clockwise latch.
The preferred embodiment of the present invention involves a latch assembly comprising a housing, a plug insert or actuator, and an engagement arm. The actuator or insert plug is rotatably held at least in part within the housing and is configured such that it may rotate between a first and a second position. The engagement arm is fixed to the insert plug at one end and thus rotates in concert with the actuator.
The range of rotation of the actuator is bound at least by first and second surfaces of a first protrusion formed in or fixed to the inner surface of the housing. The range of the engagement arm is bound at least by first and second surfaces of a second protrusion formed on or fixed to the outer surface of the housing. The range of the actuator and the engagement arm together is thus bound by the more restrictive of the protrusions as they interact with the actuator or engagement arm, and this range varies according to the orientation in which the engagement arm is mounted to the actuator.
The combination of these two different limits on the range of rotation of the actuator and engagement arm provides a surprising diversity of latch configurations and thus a surprising number of alternative ranges of operation according to the present invention. The latch of the present invention, therefore, can operate as a quarter-turn latch or a half-turn-latch. As a quarter-turn latch, the latch may be assembled such that the engagement arm may be operated in any one of the four 90xc2x0 quadrants around the axis of rotation, and it may operate in either the clockwise or counter-clockwise direction. That is, it may be assembled such that the engagement arm will rotate clockwise to engage an external catch, or it may be assembled such that the engagement arm will rotate counter-clockwise to engage the external catch.
As a half-turn latch, the latch may likewise be assembled such that the engagement arm may be operated in either one of the two 180xc2x0 halves of a full circle around the axis of rotation, and it may operate in either the clockwise or counter-clockwise direction. Further, the latch may be configured alternatively as a bi-directional quarter-turn latch. That is, in one configuration assemblage, the engagement arm will operate throughout a quarter-turn in either the clockwise or counter-clockwise direction.